Moved Core Theme Logos to CSS

In order to make it easier for a user/developer to replace logos in the core theme, I removed the hardcoded `logo.svg` and `logo-wide.svg` from the html, and replaced them with `div`s that use css background-image instead.

This has multiple advantages:
1. The user can now use any filename they want for the logo.  They are no longer forced to use logo.svg or logo-wide.svg.
2. The user can now easily use a JPG, PNG or GIF logo instead of SVG (SVG's are awesome, but used by an unfortunately small percentage of web developers at the current time.  Most probably don't even know how to make an SVG…).
3. The user doesn't have to resort to hacking the core theme template files in order to use a different filename or file type.
4. Greatly simplifies documentation instructions for how to change the logos (http://owncloud.org/theming/).

Signed-off-by: Jake Wilson <jakew@huebnerpetersen.com>
Security Update: session fixation

Previous version is vulnerable to session fixation attack in some situations, guessing non-apache-module-php5 environment. Regeneration of session id should be done here.
Update user.php to fix duplicate session-duplicate
remove fix for IE9 nav bar width
Add missing slash in URLGenerator::getAbsoluteURL(). Refs. #6840
mount: make location of mount.json configurable

do not share users data with config files

Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Removed '/'. Fixes #7035.

Not sure if that '/' is necessary but it broke things on my installation.
Test if $url is already prefixed by '/'
Do not send file list for select all on Download/delete

- When all files are selected, do not send the whole file list
- Download will trigger download for the parent folder, also works
  with root
- Delete will send "allfiles" to the server that will find the file
  list or the passed directory by itself
LDAP: prevent other configuration from being deleted when deleting the first one which has an empty prefix for historical reasons
Trashbin select all now doesn't send file list

- Fixed "delete" and "restore" actions to not send the file list when
  all files are selected
- When some files are selected, sends the current dir
- Removed "dirListing" attribute as the backend is able to compute the
  value based on the current dir
Improve users list scrolling performance

- fixed JS error when avatar mode is disabled
- added spinner at the bottom of the table
- scroll detection now happens earlier
- single/multiselect init is deferred so that the new rows are first appended
  into the list (more responsive) and initialized afterwards
- disabled users sorting after add (assuming they are always sorted on
  the server side)
Added loading spinner to users list on scroll
An admin should not be able to add remote and public services on its own. This should only be possible programmatically.
This change is due the fact that an admin may not be expected to execute arbitrary code in every environment.
Check whether the Key is set
Check whether the app is set
Added extra checks for invalid file chars in newfile.php and newfolder.php

- added PHP utility function to check for file name validity
- fixes issue where a user can create a file called ".." from the files UI
- added extra checks to make sure newfile.php and newfolder.php also
  check for invalid characters
Added file name check in webdav connector

- added file name check for the put, rename and setNames() methods which
  throw a "Bad Request" whenever invalid characters are used
- replaced \OC\Filesystem usage with $this->getFS() to be able to write
  unit tests
LDAP: improve compilation of filters
Merge pull request #7195 from owncloud/files-selectall

Do not send file list for select all on Download/delete